Question

Given the Power Supply Circuit below, examine the portion of the circuit including LM317 IC to determine the expected output voltage range the circuit will achieve by the range of adjustment of the 1000 ohm potentiometer.

78oS LM3)7 6-12V 80 tk PON Ci 680 C o. ん-- : SVoc D C. %,-12/bc

Answer 1

• LM317 output voltage range is 6-12 V.
• Output voltage is given by,
  • Vout =1.25 (1+((R2+680)/R1))
• Vout is depends on R2 which varies upto 1K.

R2	Vout =1.25 (1+((R2+680)/R1))
1000	12.91666667
900	12.22222222
800	11.52777778
700	10.83333333
600	10.13888889
500	9.444444444
400	8.75
300	8.055555556
200	7.361111111
100	6.666666667
50	6.319444444